var $chat_back_url = "tls://www.paypal.com";

var $host_header = "Host: www.paypal.com\r\n";

var $post_data = array();

var $session_id = '';

var $transaction_id = '';

public function __construct () {

dgx_donate_debug_log ( '----------------------------------------' );

dgx_donate_debug_log ( 'PROCESSING PAYPAL IPN TRANSACTION' );

dgx_donate_debug_log ( "Seamless Donations Version: " . dgx_donate_get_version () );

// Grab all the post data

$post = file_get_contents ( 'php://input' );

parse_str ( $post, $data );

$this->post_data = $data;

// Set up for production or test

$this->configure_for_production_or_test ();

// Extract the session and transaction IDs from the POST

$this->get_ids_from_post ();

if( ! empty( $this->session_id ) ) {

$response = $this->reply_to_paypal ();

if( "VERIFIED" == $response ) {

$this->handle_verified_ipn ();

} else if( "INVALID" == $response ) {

$this->handle_invalid_ipn ();

} else {

$this->handle_unrecognized_ipn ( $response );

}

} else {

dgx_donate_debug_log ( 'Null IPN (Empty session id). Nothing to do.' );

}

do_action( 'seamless_donations_paypal_ipn_processing_complete', $this->session_id, $this->transaction_id );

dgx_donate_debug_log ( 'IPN processing complete.' );

}

function configure_for_production_or_test () {

if( "SANDBOX" == get_option ( 'dgx_donate_paypal_server' ) ) {

$this->chat_back_url = "tls://www.sandbox.paypal.com";

$this->host_header = "Host: www.sandbox.paypal.com\r\n";

}

}

function get_ids_from_post () {

$this->session_id = isset( $this->post_data["custom"] ) ? $this->post_data["custom"] : '';

$this->transaction_id = isset( $this->post_data["txn_id"] ) ? $this->post_data["txn_id"] : '';

}

function reply_to_paypal () {

$request_data = $this->post_data;

$request_data['cmd'] = '_notify-validate';

$request = http_build_query ( $request_data );

$header = "POST /cgi-bin/webscr HTTP/1.0\r\n";

$header .= $this->host_header;

$header .= "Content-Type: application/x-www-form-urlencoded\r\n";

$header .= "Content-Length: " . strlen ( $request ) . "\r\n\r\n";

$response = '';

$fp = fsockopen ( $this->chat_back_url, 443, $errno, $errstr, 30 );

if( $fp ) {

fputs ( $fp, $header . $request );

$done = false;

do {

if( feof ( $fp ) ) {

$done = true;

} else {

$response = fgets ( $fp, 1024 );

$done = in_array ( $response, array( "VERIFIED", "INVALID" ) );

}

} while( ! $done );

} else {

dgx_donate_debug_log ( "IPN failed: unable to establish network chatback connection to PayPal" );

dgx_donate_debug_log ( "==> url = {$this->chat_back_url}, errno = $errno, errstr = $errstr" );

}

fclose ( $fp );

return $response;

}

function handle_verified_ipn () {

$sd4_mode = get_option ( 'dgx_donate_start_in_sd4_mode' );

$payment_status = $this->post_data["payment_status"];

dgx_donate_debug_log ( "IPN VERIFIED for session ID {$this->session_id}" );

dgx_donate_debug_log ( "PayPal reports payment status: {$payment_status}" );

if( "Completed" == $payment_status ) {

// Check if we've already logged a transaction with this same transaction id

$donation_id = get_donations_by_meta ( '_dgx_donate_transaction_id', $this->transaction_id, 1 );

if( 0 == count ( $donation_id ) ) {

// We haven't seen this transaction ID already

// See if a donation for this session ID already exists

$donation_id = get_donations_by_meta ( '_dgx_donate_session_id', $this->session_id, 1 );

if( 0 == count ( $donation_id ) ) {

// We haven't seen this session ID already

// Retrieve the data

if( $sd4_mode == false ) {

// retrieve from transient

$donation_form_data = get_transient ( $this->session_id );

} else {

// retrieve from audit db table

$donation_form_data = seamless_donations_get_audit_option ( $this->session_id);

}

if( ! empty( $donation_form_data ) ) {

// Create a donation record

if( $sd4_mode == false ) {

dgx_donate_debug_log (

"Creating donation from transient data in pre-4.x mode." );

$donation_id = dgx_donate_create_donation_from_transient_data ( $donation_form_data );

} else {

dgx_donate_debug_log ( "Creating donation from transaction audit data in 4.x mode." );

$donation_id = seamless_donations_create_donation_from_transient_data (

$donation_form_data );

}

dgx_donate_debug_log (

"Created donation {$donation_id} for session ID {$this->session_id}");

if( $sd4_mode == false ) {

// Clear the transient

delete_transient ( $this->session_id );

}

} else {

// We have a session_id but no transient (the admin might have

// deleted all previous donations in a recurring donation for

// some reason) - so we will have to create a donation record

// from the data supplied by PayPal

if( $sd4_mode == false ) {

$donation_id = dgx_donate_create_donation_from_paypal_data ( $this->post_data );

dgx_donate_debug_log (

"Created donation {$donation_id} " .

"from PayPal data (no transient data found) in pre-4.x mode." );

} else {

$donation_id = seamless_donations_create_donation_from_paypal_data ( $this->post_data );

dgx_donate_debug_log (

"Created donation {$donation_id} " .

"from PayPal data (no audit db data found) in 4.x mode." );

}

}

} else {

// We have seen this session ID already, create a new donation record for this new transaction

// But first, flatten the array returned by get_donations_by_meta for _dgx_donate_session_id

$donation_id = $donation_id[0];

$old_donation_id = $donation_id;

if( $sd4_mode == false ) {

$donation_id = dgx_donate_create_donation_from_donation ( $old_donation_id );

} else {

$donation_id = seamless_donations_create_donation_from_donation ( $old_donation_id );

}

dgx_donate_debug_log (

"Created donation {$donation_id} (recurring donation, donor data copied from donation {$old_donation_id}" );

}

} else {

// We've seen this transaction ID already - ignore it

$donation_id = '';

dgx_donate_debug_log ( "Transaction ID {$this->transaction_id} already handled - ignoring" );

}

if( ! empty( $donation_id ) ) {

// Update the raw paypal data

update_post_meta ( $donation_id, '_dgx_donate_transaction_id', $this->transaction_id );

update_post_meta ( $donation_id, '_dgx_donate_payment_processor', 'PAYPALSTD' );

update_post_meta ( $donation_id, '_dgx_donate_payment_processor_data', $this->post_data );

// save the currency of the transaction

$currency_code = $this->post_data['mc_currency'];

dgx_donate_debug_log ( "Payment currency = {$currency_code}" );

update_post_meta ( $donation_id, '_dgx_donate_donation_currency', $currency_code );

}

// @todo - send different notification for recurring?

// Send admin notification

dgx_donate_send_donation_notification ( $donation_id );

// Send donor notification

dgx_donate_send_thank_you_email ( $donation_id );

}

}

function handle_invalid_ipn () {

dgx_donate_debug_log ( "IPN failed (INVALID) for sessionID {$this->session_id}" );

}

function handle_unrecognized_ipn ( $paypal_response ) {

dgx_donate_debug_log ( "IPN failed (unrecognized response) for sessionID {$this->session_id}" );

dgx_donate_debug_log ( "==> " . $paypal_response );

}